


A Summon Gone Wrong?

by Damien_Kova



Category: Fate/Grand Order
Genre: Creampie, F/M, Oral Sex, Paizuri, Vaginal Sex
Language: English
Status: Completed
Published: 2020-11-19
Updated: 2020-11-19
Packaged: 2021-03-09 20:02:44
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,000
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27631783
Author URL: https://archiveofourown.org/users/Damien_Kova/pseuds/Damien_Kova
Summary: As a Servant that isn’t supposed to be able to summoned, Tiamat, does her best to reassure her Master that she’s not out to harm him like when she was a Beast. However, that amounts to her showing him the love that she holds in her heart in the middle of the night.
Kudos: 26





	A Summon Gone Wrong?

After everything that happened in Babylonia, the Final Master of Chaldea felt that it was time to try and summon for some more people to help fight on their behalf. Whether it be Heroic Spirits that were as recognizable as King Artoria Pendragon, spirits with a twisted origin such as Gorgon, or spirits that seem to be able to do whatever they want like Merlin. Any help at this point would be welcome. And it brought a smile to the Master’s face to know that they were able to summon for multiple units at once, increasing their chances of getting a unit that would be better for them in battle.

As the Master stepped into the room that had been designated for summoning Heroic Spirits into Chaldea, he saw just how mangled it had become after everything that happened with Olga and Professor Lev. That day felt like it had been ages ago at this point, but deep in his heart, the young Master knew it had only been a few weeks at the most. However, what happened with Olga was exactly why he felt the need to bring more help to their side. Anything they could do to win out would be a benefit to him.

He held his Saint Quartz tightly in his hands as the doors to the summoning room closed behind him. In the back of his mind, he could picture a few Heroic Spirits that had the highest chance of being able to appear by his side. And as he crushed the crystals in his hands, sacrificing them in order to pull those spirits to his sides, the world around him seemed to fade away. The same way it had when he first summoned a spirit or two into Chaldea. However, when he opened his eyes again, there weren’t multiple spirits standing in front of him, but instead only one. A spirit that he had just recently seen in Babylonia. A spirit that seemed to be able to corrupt and twist the system with her presence. In front of him stood a human-sized Tiamat, with her eyes open and her hands at her stomach.   
  
When she noticed that the young Master’s first instinct was to turn and run, Tiamat quickly shook her head and shouted for him. But her voice wouldn’t come out for a moment, only the sound of a scream that seemed to linger in her throat. Fortunately, once that moment was over, Tiamat was able to find her voice again. “Please! Wait! I know why you’re scared, but I can promise you have nothing to fear! After everything that happened in Babylonia, when I finally saw the chance to be able to see you face to face again… I wanted to take this moment to apologize and be of use! I swear! I’m not the same Beast that I was back then!”   
  
As he waited for the doors to the summoning room open, the young Master felt a strange sense of understanding to what Tiamat was saying. It wasn’t normal for Servants or Heroic Spirits to change their classes on a whim, but there was another Beast that changed her class in order to better observe the things around her. He couldn’t quite remember her name at the moment, but that was enough of a reason for him to be cautious around Tiamat. He nodded his head as the door finally opened. “I… I guess it’s fine for you to come with me. After everything that happened… Don’t blame us for being cautious of you, though.”   
  
**********************************************************   
  
From the moment that she got summoned Tiamat had spent the day doing her best to prove to those around her that she was only here to spread the love that she felt toward the world and humanity. She understood just why they were cautious of her, knowing exactly what she did in the past when they were in Babylonia, but she was here to prove that she had grown past that and wanted to show her thanks. Fortunately, she had been told to spend the night in her new Master’s room when he slept. That her final test to see if she truly was safe to keep around would be to watch over him while he sleeps.

As she stayed with him over the night, Tiamat found herself slowly growing more and more absorbed in this young man’s features and his looks. She thought that he was very cute for a man his age, and that he shouldn’t have to suffer the burden and stress of saving the world without anyone there to help him destress a little bit. And that’s when a thought popped into her head. She was the mother of all creatures and the loving deity of the world. What was stopping her from crawling into his bed and giving him that attention?   
  
The moment that she came to this realization, Tiamat immediately started to climb into her Master’s bed, paying careful attention to stay under the blanket that he used. Fortunately, he seemed to be a slightly heavy sleeper, so getting his pants off of him was no trouble at all. But the moment that she got a good glimpse of his cock, Tiamat knew that she was making the right choice. A slightly heavy breath left her lips as she wrapped one of her hands around the base of his shaft, placing a few gentle kisses against the tips. “I hope this also helps you trust me a bit more, Master…”   
  
A loving and gentle tone filled her voice as she took the first few inches of her Master’s cock into her mouth, a quiet moan rumbling in her throat as she allowed her eyes to flutter shut. For a single moment, Tiamat allowed herself to simply sit back and enjoy the flavor of this young man’s shaft against her tongue. She wanted to linger forever and just enjoy the flavor that coated her tastebuds. But she knew that she couldn’t. And that was exactly why Tiamat started to carefully bob her head up and down the length of her new Master’s shaft. She took her time, taking inch after inch into her mouth before stopping when she reached the base.

The moment that she reached the base of her Master’s cock, Tiamat swallowed around his member. In the back of her mind, she was reminded that she still had incredible strength for someone of her size and she should be careful. But that didn’t stop her from enjoying the way it felt to have her Master’s shaft buried deep into her throat to the point where it felt like it would reach into her stomach.

Her eyes started to roll into the back of her head as she picked up the pace and started to move along his shaft once again. Tiamat kept her tongue moving along this young man’s member as she bobbed her head, wanting to make sure to slather each and every inch of his length in her love. Even as quiet and blissful moans started to rumble in her throat, vibrating around his shaft and causing him to moan in his sleep, Tiamat didn’t miss a beat. She continued to move at her own pace and rhythm. At least, she did her best to with the blanket getting snagged on her horns ever now and against when she lifted her head back up.

After a moment or two of sucking her Master’s cock and relishing in the flavor that coated her tongue, Tiamat brought her free hand above her head and threw the blanket over her body as she moved. A blissful sigh escaped from her nose when she was able to move freely once again, taking her Master’s cock to the base as he slept through this. From the way he started to throb and pulse against her tongue and her lips as she moved, it seemed that he was going to blow his load relatively soon. And somewhere in the back of her mind, Tiamat was hopeful that he would fill her throat while he slept. Or better yet, that he would wake up and purposefully cum inside of her mouth.

However, now that she had thrown the blanket off of her body and over the side of the bed, exposing herself and her master’s nude form to anyone that could walk in, she arched herself in a way that allowed her to reach her free hand between his legs so she could tease his balls. A smile came to her lips as she cupped his hefty sack, shocked but elated to learn just how full his balls were. Unfortunately, just as she started to cup his balls, massaging them with her fingers, Tiamat could hear her Master groaning at his pillow, meaning that he was waking up to her touch.

When he had gone to sleep that night, Chaldea’s Master knew that Tiamat was going to be watching over him. It was his idea to have her doing it, after all. But he didn’t expect to wake up to the feeling of her tongue dancing around his shaft and her fingers massaging his balls. A faint but blissful smile came to his lips as he came in her throat in the same moment that he fully woke up. The world around him came into view as his cock erupted in that wet and welcoming mouth. And he couldn’t think of a single reason to complain as he poured rope after rope of his thick, heated, and potent seed into her throat and her mouth.

Of course, Tiamat let out a shameless and excited moan when her new Master came in her mouth. The feeling of him flooding her mouth and feeding her his seed was enough to make her pussy quiver and ache. And when she started to swallow down his cum, savoring the flavor that coated her tastebuds, she knew that she had to do more in order to get another taste at his seed. Luckily for her, Tiamat felt her Master’s hand grab onto one of her horns, using it as a grip and leverage in order to pull her off of his shaft.

The moment that her lips popped off from around his member, Tiamat let out a gentle and loving giggle as she looked up at him. “I’m sorry for waking you, Master. You were sleeping so soundly that I couldn’t help but feel like I needed to show you a little bit of love. After everything you’ve been through, I think you should have someone to help you relieve some of your stress, right?~” Before letting him say a single word, Tiamat smirked and cupped both of her breasts in her hands, wrapping them around his member as she adjusted her lower half to allow her to lay almost flat on the bed.

Almost immediately, Tiamat felt the heat of her Master’s cock in her cleavage, making her groan as she looked at him. Something about the way that his hot, thick, twitching dick sat between her breasts like he was waiting for her to bring him more pleasure lit her up inside. Maybe it was the way she could now look into his eyes, seeing the slight bit of lust that lingered within them. Maybe it was the fact that he was actually giving her a chance to prove herself by keeping this up. Maybe, just maybe, it was the simple fact that Tiamat had always craved the feeling of a cock between her breasts and now she had it.

She carefully dragged her tongue along her lips as she started to move her large mounds up and down the length of her Master’s saliva-coated member. “Thank you for giving me a chance to prove myself to you, Master. I hope that I’m doing a good job so far.” Tiamat playfully stuck her tongue out at the young man as he groggily woke up with his dick between her legs. Sure, his eyes were open a minute ago, allowing him to see her as he came down her throat. But now? Now, he was clearly awake and able to enjoy the soft feeling of her breasts squishing around his shaft.

In the back of his mind, somewhere deep, deep back there, the young Master knew that he should stop Tiamat from what she was doing. Whether it be because of how he felt toward Mash or the fact that Tiamat could be doing this to trick him. He knew he should stop her and see how she reacted. But the way her breasts moved along his member was far too good for him to be able to pass up on. Especially when she leaned her head down and started to swirl her tongue around the tip of his member, bring him even more pleasure than she was a moment ago.

Waking up to cumming in her throat was a surprise that he wasn’t expecting, even if she was the “loving mother” of all creatures on Earth. But for it to continue past that? For her to keep pleasing him simply because his cock was still hard? He couldn’t bring himself to disagree with something like that. Especially with the way she wrapped her lips around the very tip of his shaft and playfully sucked on it, swirling her tongue around the head of his cock in the same moment. It was a very lewd and wonderful sight for him to wake up to. And he didn’t want to pull himself away from it. “W-Well… You’re trying so hard to prove that you’re not here to hurt anyone… The least I can do is give you a chance… P-Plus, the fact that you’re able to speak shows you’re not the same Beast as back then...”   
  
Another giggle rumbled in Tiamat’s throat as she listened to her Master. He was such a sweet man to her, allowing her to do her best for him. It prompted her to pick up the pace at which she moved her breasts, pressing them together to be more flush around his shaft as she moved them. And each time that his tip poked out from the top of her cleavage, Tiamat expertly placed a gentle and affectionate kiss against it. She wanted to show him that she was here to spread her love and treat those of Chaldea with respect and love.

Fortunately for her, as her eyes were locked on his own, she was able to see how his lust and love for her grew with every moment. And she could also feel his shaft pulsing between her breasts, showing her that he was going to cum again at any moment. “It’s okay, Master. Don’t hold back. I want you to cum all over me. Shower me in your love and gift me with your seed. I promise I won’t waste a drop.~” Tiamat dragged her tongue along her lips as she pushed her breasts down to the base of her Master’s shaft, leaning forward in order to take it into her mouth once again. However, she didn’t get the chance as he reached his peak a moment before she could.

Rope after rope of her Master’s thick, heated, and potent seed splattered against her face, coating her skin in his spunk as he groaned a little bit above her. A bright and lustful smile came to Tiamat’s lips as she closed both of her eyes, opening her mouth in order to catch as much as she could. Unfortunately for her tastebuds, most of her Master’s seed splattered against her face and dripped down onto her breasts, leaving her mouth craving and wanting more but being unable to get it.

However, that didn’t stop Tiamat from smiling and bringing one of her hands from the sides of her breast to the tip of her soft mounds, swiping a finger through one of the globs of cum that rested against her skin. With that bright smile still on her lips, she didn’t hesitate to open her mouth and pop her finger into it. The moment that her finger touched her tastebuds, a lurid and excited sound rumbled in her throat. A sound that made it clear that she wanted more from the man she was showing her love to.

Of course, when her Master’s orgasm subsided and she was left feeling his hard cock twitching inside of her cleavage, Tiamat found her desires starting to get the better of her. Somewhere in the back of her mind, she knew that she should stop now and allow her Master to go back to bed and rest. But she didn’t want that. Her body ached, craved his touch, desired him filling her and pumping into her over and over again. Her body wanted more of him. And she was going to get it.

Tiamat playfully dragged her tongue along her lips as she started to make her way up her Master’s body, crawling above him until she was able to straddle his lap. But instead of just planting herself down in his lap and letting him have his way with her, Tiamat instead carefully placed her soaked pussy against her Master’s hardened shaft. And she playfully started to rock her hips back and forth against it, purposefully teasing his member with her pussy lips. “I hope you don’t mind being away for a little bit longer, Master… I gifted you with my touch and love, allowing you to soak in it. But now… My body craves your touch and soaking my insides in your love.”   
  
Slowly dragging her tongue along her lips, Tiamat started to gently hoist her hips into the air, shivering in delight as she felt his shaft continue to press against her pussy lips as she rose. She couldn’t help but look into her Master’s eyes as she brought one hand to his shoulder and the other to his crotch, carefully wrapping her fingers around his shaft and pointing his tip directly at her entrance. With her instincts starting to take over the way she moved, Tiamat quickly and eagerly dropped herself down onto her Master’s lap, forcing each and every inch of his thick and wonderful shaft into her cunt in one swift motion. One swift motion that caused her to throw her head back in pure and utter bliss, a loud and shameless moan spilling from her throat.

Somewhere in the back of his mind, the young Master was reminded that he shouldn’t be doing something like this with his Servants. Especially one that tried to kill him so readily in the past. However, he couldn’t help himself anymore. The feeling of her surprisingly soft skin wrapped around his shaft was enough to hook him in, the way her tongue danced around his shaft was enough to make him crave her. But the feeling of her inner walls tightly convulsing and spasming around his shaft in delight? That was more than enough to make him almost addicted to Tiamat’s body.

After a moment of Tiamat remained still for a moment, the young Master started to rock his hips first. Her inner walls remaining tight like a vice around his shaft left him craving more. Something that he quickly tried to obtain for himself. He quickly grabbed onto both of Tiamat’s hips to keep her in place as he started to thrust his hips upward into her. The first couple of thrusts were enough to push her hips a few inches above his own, leaving them both able to feel a delightful difference from when every inch of his shaft was buried inside of her and when he pulled out of her. After those first few thrusts, he didn’t hesitate to pick up the pace and work himself into a rhythm that he was happy with.

Once her Master worked himself into a rhythm that he was happy with, Tiamat quickly followed his example. She used the rhythm of his thrusts to dictate the way that she moved her body. Whenever he would thrust upward into her, she pulled her hips back. And when he dropped his hips down, leaving only a few inches of his wonderful shaft buried inside of her, she would push her hips forward. And in a matter of moments, the two of them were moving in sync, moaning and writhing with the other as they made love.

Tiamat felt her heart racing in her chest as she gave into her carnal desires, being the mother of all creatures making her crave having this young man fill her womb and make her into a mother once again. However, she couldn’t bring herself to say anything as nothing but moan after moan spilled from her lips, the pleasure that she felt being heard loud and clear in the room around them. Luckily for her, no matter how loud she got, Tiamat wouldn’t disturb anyone who was sleeping in the rooms around their own.

On the other hand, some part of the Heroic Spirit wished that she could be heard. Wished that she and her Master would be caught in the act and she could greedily claim this young man as her own for the rest of her time with him. But as she looked down into his eyes, seeing the lust and love that swirled within them, she knew that it wouldn’t be a smart idea to do that. However, that wasn’t going to stop Tiamat from rocking her hips a bit harder than she was a moment ago, increasing the intensity of how she moved and hoping that it would bring her Master to orgasm inside of her.

Luckily for her, the harder she moved, the closer that her Master got to his third orgasm. And as he moaned and bucked underneath her, thrusting upward into her snatch still, he couldn’t deny the intense pleasure that coursed through him. At this rate, he was going to cum inside of her and make sure that every single drop of his seed filled her womb and stayed in there. And, in his lust-addled mind, he couldn’t think of a single reason that would make that a bad idea. His lips curled into a smile as he reached the peak of his bliss, and erupted inside of her without any kind of warning. Only a grunt of pleasure rumbling in his throat as he came.

Of course, that wasn’t a problem for Tiamat. When he erupted inside of her, she got exactly what she wanted out of him. A flood of his seed pumped directly into her womb as she crashed herself down onto his lap, taking each and every inch of his shaft in one swift thrust once again. Every single drop of his seed pumping into her womb was another that pushed Tiamat and through her orgasm. Not only did her Master reach his peak and cum inside of her before she came, but the feeling of his spunk filling her sent her over the edge as well.

Throwing her head back in pure and utter bliss, Tiamat screamed in pleasure as her inner walls clamped down like a vice around his shaft. And on pure instinct, she started to rock her hips once again, trying to wring each and every drop of cum that she could out of her Master’s shaft. She wanted every drop she could get. But when the pleasure became too much for her, just in time for him to finish erupting inside of her, Tiamat found herself falling to her Master’s side, her arm hitting the bed before she rolled over onto her back.

Hot and heavy breaths spilled from her lips as she allowed the afterglow of her orgasm wash over her. Of course, her Master had it worse than her, just coming off of his third orgasm compared to her first. But Tiamat couldn’t stop herself from smiling as she turned her head to look at the young man that would likely make her a mother once again. Coincidentally, as that thought rushed through her mind, she noticed her Master adjusting himself in order to lay over her body, their lips only inches apart as she felt his shaft press against her pussy once again.

In the matter of an instant, Tiamat felt her Master’s shaft fill her pussy once again, stretching her inner walls and making her scream out in pleasure in the same moment. Her lips curled into a bright smile as she immediately wrapped her arms around his neck, holding him as closely as she could. Close enough for their lips to meet for a heated and passionate kiss. A heated and passionate kiss that quickly led to a second. And then to a third. Before she knew it, Tiamat found herself making out with her new Master in an eager and loving fashion. All while he thrust himself into her over and over again, fucking her missionary.

On the other hand, her young Master couldn’t seem to help himself anymore. Still in the back of his mind, he knew he shouldn’t be doing something like this. Not only was it wrong on some degree to fuck a Servant, but he had his feelings for other people to think about. But none of that seemed to stop him as he hammered each and every inch of his thick, throbbing shaft into Tiamat’s tight pussy, filling her up the same way he did when she bounced on his lap.

Each and every kiss that she placed against his lips, the young Master quickly returned to Tiamat. It wasn’t a matter of how many kisses the two could share as he rocked his hips back and forth, but instead a matter of accepting every single ounce of Tiamat’s love that he could while giving it back to her. And from the way her arms seemed to tighten around his neck as her inner walls tightened around his shaft, it seemed that he was doing a good enough job at keeping her happy.

Of course, it didn’t take long for Tiamat to start rocking her hips with his own, moving herself in a perfect rhythm with her master in order to bring them both as much pleasure as she could. Her body reacted to each movement that her Master made, causing her to move with him and against him, accentuating the way he scraped along her inner walls as he hammered against her womb. Combine that with the way their lips danced in kiss after kiss after kiss, and Tiamat’s heart racing in her chest had more than enough reason to do so.

The fact that someone so young and so determined to save the world around him chose to take this moment and fuck Tiamat of his own accord caused her heart to skip a beat in her chest. Some part of her couldn’t believe that he was willing to keep going and chasing toward a fourth orgasm after he had already fucked her and given her what she wanted. But she wasn’t going to dare tell her Master to not fuck her like this. Especially when she finally pulled away from his lips, taking a deep breath and letting a loud and shameless moan radiate from her throat. “It feels so good, Master… Don’t stop. Just… Be sure to use my body as much as you need. Fill me with your love and your stress. I’ll take it all and return it to you in a wonderful display of affection.”   
  
Her word seemed to spark something in the young man that was fucking her so well, his pace quickening and the intensity of his thrusts increasing in the same moment. Tiamat didn’t know if she had just managed to coerce her Master in letting out everything he felt into her or not. But she was happy all the same to feel him throb and pulse against her inner walls as her started to mold them to the shape of his shaft.

Tiamat leaned her head back as she held her Master close to her still, refusing to let him get more than a few inches away from her lips as he hammered into her. She kept her eyes open, though, looking into his eyes in order to see just how he felt. And her heart skipped a beat once again as she didn’t see lust and love in his eyes anymore, but instead a desire to simply breed. It was only for a moment, but that moment was enough for Tiamat to grab on tighter to her Master’s body, her inner walls tightening around his shaft in response. “Do it, Master. Cum inside of me and give me every drop of your seed.”   
  
Almost as if on queue, the young Master slammed himself as deep into Tiamat as he could in this position, stuffing her pussy full and letting the tip of his shaft kiss the entrance to her womb before he came. Rope after rope of his thick, potent, and fertile seed flooded his new Servant’s fertile womb as he heard her scream out in bliss in the same moment. He didn’t move his hips as he erupted inside of her, though, wanting every drop of his spunk to stay in her womb.

Because of this, Tiamat reached her orgasm as well. Her inner walls greedily clung to her Master’s cock as it erupted inside of her, accepting each and every drop of his seed. But in the same moment, Tiamat’s emotions ran higher than she expected and she couldn’t keep herself from screaming out as she came. “I love you, Master! I love you so much!” Her heart raced in her chest as he finally stopped cumming inside of her, allowing himself to fall to her side a moment later with his dick still buried deep inside of her. “I mean it, Master. I love you…”


End file.
